Apparatus for forming dental inlay castings



Nov. 20, 1923 1,474,620

R. T. CASE I APPARATUS FOR FORMING DENTAL INLAY CASTINGS Filed Dec. 29, 1920 i v Be it known that LROLLANo Fatentcd Nov. 20, 1923.

HOLLAND, n'casn, or LA cnossn, WISCONSIN.

; aise? APPARATUS non romaine DENTAL INLAYCASTIILSGS;

Application filed December '29, 1920; S eria1'1 1'o'. 433,904, i

To all whom it may 00mm. I

I T. CAsn, a citizen of the United States, and resident of La Crosse, in the county of La Crosseand State of WVisconsin, have'in-vented new and useful Improvements. in Apparatus for Forming Dental Inlay Castings, of which the followingi s a description; reference being had to the accompanying drawings, which are a part of this specification.

This invention relates to improvements in apparatus for form ng dental inlay castings, In inlay casting precious or other metals,

a mold is formedaround a wax pattern and when completedthe wax is melted and discharged fromthe mold. The mold is'formed with: a tapered mouth leading to the recess to remove the casting As there, is a per: ceptible spacebetween the crucible and the mouthofthemQId and from the outer portion ofthe mouth to; the mold recess, the

a molten metal in passing from' the crucible passes through the space and-drops on the inclined portion *of' the mouth of the mold and climbs up said inclined portion and into the mold recess, and is more or less'chilled V beforewit; reaches said mold recess with the .result that-the metal does-not completely fill 40 all of the minute'crevices, ofthe mold recess and thecasting is not as perfect as could be I j des'iredr Furthermore, the molten mass of metal in passing from the crucible to the mouth of the mold will splash against the ,mouthportion-ofthe mold and divide into small particles, and these small particles will become chilled and partly hard before .they enter the mold and form an imperfect casting -"w i ,;'-,T he crucibles used in dental inlay castin (are. comparatively expensive and very often crack or break when used but a few times.

, It is, one of the. objects Iof-the' present in-;

.vention to overcome the before =menti oned objectionable features and provide an apre s referees nt inlay ee ,sist in' filling the recess.

the purpose described. y

which molten metal is guided driven I into-themold recess infthe'v most directand i efficient mannerwithout permitting the mol; ten metal to splash or to become ehiillediibeforefit enters;the.1 noldrecess.v

mold are integral andarenewjly constructed stroyedto remove the casting i further object of the invention is to PIOVldt-l an apparatus for. forming dental inlay castingsin which the crucibleand the V i for each inlay casting madeand are-de- A further l j of the invention is to provide an. apparatusfor forming dental inlay castlngs 1n which the wax pattern may be so positloned onthespruepin as to form that in supplying molten metal to the recess, gravity as well as centrifugal forcewillas- A? further object of the invention is to a mold with the. lasting recess located so provide a method of andapparatus for :1 formlng dental inlay. castings in which the operator may easily change the form of the crucible, portion of the. apparatus which holds the molten metal to-suit any condi v tion which might arise in casting unusual V shapes or rotating the mold in any direc tion.) Aljurther object of the invention Qis; to provide an apparatus for casting dentaLinlays which is ofsimple construction, is efv; ficient lnoperation' and is well adapted-for With the above a d I other;

and its partsland combinations asset forth in .the claims, and all equivalentswthereof f In the: accompanying drawings, .inswhi ch same parts in allof'theviewsp v the same referencev characters;indicate the of the apparatusused infformingvthe. combined cruclble andcastmg mold; H

Figs 2 is a perspective view of a-nother" portionof the apparatus used informing thecombined crucible'and mold a i. Y, iee s' we, .7 the nventlon cons sts of theamprovedjapparatus for-forming dental nlay .Icast ngs Fig. L is a perspectiveaview of i Fi'g, 3'15 a side view, parts being shown in section,v of'the apparatus illustrating one of the steps i using the improved appara- F ig; eisa perspectivex'view.of the? bined crucibleand mold -jillustrating an other step in -the useof the; apparatusg 1 Referring-to the drawings-,the' apparatus s e m e he, S ps: of; the-r mproved molding process consists of a tubular fiask16,a main body member and sprue pm holder 17, a crucible bowl former 18 and a sprue pin 19. V

The flask 16 is preferably of cylindrical form with its lower half section cut away as indicated by the numeral 16 to receive the inner fiat face portion 17' of the main body member 17 as shown in Fig. 3. Said main body member 17 is formed with vertically extending dovetail grooveways 20 for slidably receiving the vertically extending dovetail guides 21 on the inner flat face 18 of the the bowl former 18 and for holdingthe body member and bowl former firmly in assembled position, as also shown in Fig. 3. The bowl former is provided with a medial outwardly projecting rounded bowlformer portion 22 which merges upwardly into a half conical portion 23 which with a half conical portion 2 extending upwardly from the body portion 17 forms a conical upper portion. The apex of the body conical portion is formed with a vertical opening 25, for receiving the sprue pin 19, which supports the pattern 26 preferably formed of wax. I

The inner face of the body member 17 is also provided with guide grooves 27 into which slidably extend the edge portions 28 of the flask 16. Several sets of these guide grooves are of different sizes;

The upper face of the body member is formed with half circular shoulders 29 in stepped formation to fit different sizes of flasks and over one of which shoulders the half circular edge portion 30 of the flask extends and holds the parts together. In carrying out the steps of the n'i'ethod, the wax patternismade of the tooth cavity or other part and is mounted on the'upperend portion of the Sprue pin 19 and said pin is inserted in the pin hole 25 of the body member and the bowl former member 18 which have been assembled. The flask tube 16 is now placed over the bowlformer member and thehalf circular portion of the body portion member and an investment compound or other molding material 31, while in plastic condition, is pouredinto the upper openend of the flask tube while the lower end of the tube is closed by the surface it is resting upon. Assoon as the investment compound. has set or become hard, the body is slid downwardly in a line parallel to the flask to disengage the bowl former member and the mouth forming sprue pin-. or the spree pl may also move downwardly with the body member; or removed as desired. When these two parts are remo'i 'ed, the bowl former member" may be easily removed laterally, and upon the application of heat to the attern 26, it will melt and flow out o'fith oldedi ece'ssf 31. The resultant mold esta es-e the mold recess 3t, before menprovided to accommodate -flasks.

nearing pattern, a crucible bowl fo tioned, the integral crucible bowl port-ion and the tapered mouth leading directly 'into the mold recess 31. The combined mold crucible and melted by a flame and blow' pipe. When the metal is at the proper'temperat-ure, the casting 'machine is rotated to cause the molten metal to travel upwardly directly into the mouth of the mold" and into the mold recessby centrifugal forcein a most direct path without loss of metal or heat and the metal will completely fill the mold recess while in a fused state and as cooled by further rotation of the mold aperfect casting will be made. \Vhen the casting operation is completed the investment material is broken and removed from the tubular flask to remove the casting. In making special castings the crucible bowl may be easily scraped to any desired shape to direct the molten metal into the mold, and the pattern may be mounted upon the sprue pin to position'the casting recess at any location with respect to the mouth of the re cessto aid the flow of the metal therethrough. By positioning the major portion of the pattern on the side of the sprue pin nearest to what willbe the bottom of the mold, the course of the molten metal will be mostly downwardly after it passes through the mouth of the mold, with the result that gravity will materially aid infilling the mold.

From the foregoing description, it will be seen that the improved apparatusprovides a new crucibleand mold for each casting and that the integral construction eliminates many undesirable features adherent tOiriTethods and apparatus now in general use. f

WhatI claim as my invention is:

1. Means for forming a mold, comprising f nected thereto for supporting a pattern, a

crucible bowl forming member to permitthe removal of the mold removably connected to the body member, and a tubular investment con'ipound while in a fluid state a body member, a sprue pin removably conto form when hard a mold having an in:

tegral crucible portion. p

2. l leans for forming a mold, comprising a body member, a sprue pin remo connected thereto for'supporting disapmember slidably removably connected body member to permit ovalof the mold, anda tubularflaslt member steamy inclo'sing the s ree pin and the; bowl fo rnt in meniber for receiving an investment com oundwhi-le in a fluid state to form when hard a mold having anintegral cible portion, said body menmerbeing fiist member.

3. Means for forming a mold, comprising a body member having a pin openingm its upper portion and grooves on one side, a sprue pin removably extending into said opening for supporting a disappearing pattern, a crucible bowl forming member slida'bly removably connected to thebody memher, there being a dovetail groove and guide slidab-le connection between the two members, and a tubular flask member having an offset portion slidably extending into the body member grooves and inclosing the sprue. pin and the crucible bowl forming member for receiving an investment compound while in a fluid state to form when hard a mold having an integral crucible portion, said body member being first removed from the flask member to permit the removal of the crucible bowl forming member.

4. Means for forming a mold, comprising a body member having a shoulderedportion and a pin opening in its upper portion and grooves on one-s1de,' a spruepin removably;

extending-into said opening forsu portlng a disappearing pattern, a crucib e bowl forming member .slidably removably connected tothe body member, there being:

dovetailgroove and guide sli'dable connec- 5 tion between the two members, and a tubular flask memberhavingan offset portion slidably extending into the body-member grooves and inclosing the sprue pin' 'and the cruclble bowl forming member for: re- P I ceiving an investment compound while in a 1 fluid state to form when hard a mold havin an integral crucible portion, portion o said flask member extending over the shouldered portion of the bodymem-ber, said bodyv member being first removed from the flask. member to permit the removal' olf the crucible bowl forming member.

In testimony whereof, I afiix my signature.

ROLLAND '1. CASE; 

